Hygrostat.



V. F. DAVIS.

HYGROSTAT.

APPLICATION FILED 1123.16. 1910.`

Patented Mar. 3, 1914.

ATTO EYS MIIUMIIA N-ANMIIAMI IDUWAIIIIMIWIN Il\ l.

portioning the lrodsand ltlie barthat for Yconjunction with means or liumidifying the in means which is preferably in the shape tive lengths of the wet rod, the dry rod and .'theconnecting.rod. L y

bfwill operateto-eontrol, inconjunction withl of moisture to theichamber or receptacle in UNITED STATES PATENT oEEicE. vEnNE'E E. Davls, 'or' one-NGE, NEW JERSEY.

Bpeeioation of Letters Patent.

Patented Mar. 3, 1914.

Application tiled February 15, 1910. Serial No. 544,042.

To all whom. it may concern.'

Be it known tliat I VEaNEiz F.ADAvIs, a citizen of the United States, residin at Orange, in the county of Essex and tate of New Jersey, have invented certain new and useful Improvements in Hygrostats; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to figures of reference marked thereon, which form a part of this specification.

This invention relates to a hygrostat or liygronieter which is adapted tomaintain a percentage of humidity in the air operating by the expansion and contraction of rods which ai'esubjected to wet and dry bulb temperatures to control the expansion and contraction of such rods.

The apparatus is desi ned to be used in atmosphere and operates to cause or prevent the a( mission of moisture into the air.

The apparatus comprises a wetjrod and a dry rod and also a connecting means, the wet rod and the dry rod and the connecting means having` the same eoeilicient of experi sion and controlling, by their expansion, a certain pereenta e of liumidit which percentage is depen( ent on the re ative lengths of the wet rod, the dry rod and the connectrod.

'llie apparatus consists of such rods connected by a lever so that the difference of the expansion between thelwetrod and the.. dry rod actuates the lever to move the connecting means, the lever having an adjustable connection with one of the rods so that thelevcr when adjusted will maintain a constant difference between the wet bulb temperature corresponding to the 3er cent. humidity the machine maintain before adjustment and the actual wet ulb temperature. -The percentage of humidity that'is to be maintained is controlled bythe rela-- The vinvention further c'onsistslin so proabout 10% of relative humidity the same bar thewet' rod. andl the dry rod,"the admission which the apparatus is placed, the adjustment between the 10% being possible by a manually operated screw or similar device.

The invention is illustrated in the accompanying drawing, in which- Figure 1 is a side view of the device connected with a liumidifyin means. Fig. 2 is an end view thereof, an Fig. 3 is a view from the other end. Fi 4 is ay section through a. portion otl the tavice, illustratingr ont; o the rods with means for keeping it we The device comprises a suitable base 10 on `which can be mounted a support 11 which acts to hold the valves necessary for controlling tlie liumidifying means, which support 11 has, projecting therefrom, two rods 12 and 13 which are made of material that is comparatively easily influenced by tem- Eerature chan es, and I prefer to use hollow russ rods, alt iough any other suitable metal can be employed these rods 12 and 13 having the same coeiiicient of iexpansion, one of the rods, as 13, being maintained dry, and the other rod, as 12, iaving a trough 14 arran ed beneath it, this trough 14 being preferab y attached to the support 11 fand having a slotted opening 15 initstop. A cloth or other fabric 16 acts as a wick and by its capillary attractionkeeps the rod 12 wet for the most of its surface so that while the rods `12 and, 18 are y similarly affected by temperature, the rod12, on account of its wet condition, will be. influenced .by the amount of humidity in the air, affecting the evaploration of, the moisture on the rod 1 2 so t atif the air has a 'high percentage of humidity, evaporation from the moistening means and from the rod 12will beslow and the rod 12 will yexpand because it is allowed to become warmer. A low percentage of humidity in the air will cause a quick evaporation, consequently a lowering of tem- Brature on the rod. 12 and the rod 12 will contracted.

In a suitable bearing 17, on the end of the rod 12, is swiveled oiie end of a lever 18 which is pivoted at its other end, as at 1t), to the end of a bar 2O which I prefer to `make of the same material as the rods l2 and 18 so .that it will'expand or. contract. with them under temperature changes. lhe lever 18 has an adjusting screw 21 therein whichbears against the end of the rod 13 andl may be suppliedwith an index linger 22 registering on a dial 2B. The screw 21 is Yoperates a valve 26 which in turn-,acts to used for adjusting the device to regulate-the ratio between the lengths .0L-the .roden-12,.

13 and 20. The bar 20 is connected, on the end opposed to the lever 18, to xuvalvev lever'.

24 which is pivoted to the supports 25 and actuate a relay lever 27 by means of the diaphragm 28, the relay lever 27, when op` through the pipe 82 ant the pipe 88 to yopcrate the diaphragm vulve 34 w iichin turn operates the valve 36. These valves are well known in the art of temperature regu` lation and the interior construction of the valve is not described herein, since the operation of them is well known to any one skilled in the art, the valves, however, operate to either admit or cut ofi' fluid which enters through a pipe 80 from any suitable source of fluid pressure and passes through the pipe 81 und then throu h the valves and a second pi e 32 through tie outlet pipe 38 and into a diaphragm 84, and acting against a spring 35. The fluid, when admitted` causes a closing of a valve 86 which is fed by a steam pipe 87, kand when open,` throws moisture into the air of the room or n arttive pei' cent. of

ment, 'having it spread or scattered y a suitablesprinkler iead 88, and in practice it is usual to drive the steam into the air by a blower 89.

It must be remembered that the difference bctween`the'wet' bulb temperature andthe dry bulb temperature becomes greater when the dry bulb'temperature rises and the relaiumidity remains the same andy it'is necessary wlien'tlie rods and the bararcmade of material having the same 'coctlcent'of expansion for the bar 20to "compensate for this'ditl'erence'by the ratio 'ofits'le'ngth to'that of the rods'12 and 13 when' lthe rods 12 and ,18 'are of the saine length and have the saine coefficient of expansion. This rat-iois determined by the allowing formula, whenfl, is t ie low dry bulb temperature'.

w, isthe low wet bulb temperature.

(l, sthe high dry bulb temperature.

w, is the high wet bulb temperature.

. F'i's the product of-.

' lu is the distance between rods 12 and 18.

n is the distance betweenrod 18'and bar, 20. D is the length of rod 18 at d'. f i M 15th@ iengthef bnr soia d.. i

then, I

[(Y-X) XF-l-Yl -Z be the sinne at any dry bulb temperature when the relative humidit is the proper percentage. These proportions are evident romthe following formula:

-- C is the coeiliccntl of expansion.

i L' is the length.

l is the tem ierature.

' X is the pro( uct of CXLXT for iod 12.

Y'is the product of CXLXT for rod 18. Z is the product of CXLXT for har 20 (the length of bar 20 is determined by for- Amula above).

F is the product of n is the distance between rods 12 and 13.

k is the distance between rod 18 und bar 20.

It is not necessary that a bar 20 be of a different length for each per cent. of relutive humidity at which the hygrostat is to o crate, the variation beine* so slight that tie same bar will do for about 10 degrees, being adjustablefby the screw 31, within these limits. For instance I will use one bar to operate between 26% and 35% relative humidity another from 36% to 45% relative humi ity and so on. This is consistent in view oi the relative humidity at dierent temperatures both wet and dry bulb, as shown in the following table.

Dry bulb Wet bulb Rel. hum. lamp. i'stemp. is-

30% 30 F. 23 F. 30 o 60 F. 45 F. 80 00 F. 00.5 F. 40 0 30 F. 24.5 F. 40 0 00 F. 47.5 F. 40 o, 90 F. 70.5 F. 50% 30 F. 25 F. 50% 60 F. 50 F. 50% 90 F. 74 F. 60% 30 F. 25.5 F. 60% 60 F. 5l F. 60% 90 F. 76 F.

The operation of the device is as follows: When the humidity is low, evaporation from the wet rod 12 is rapid, the wet rod 12 contracts, pulls/in on 'the end of the lever 18 which 1s fulcrumed on the screw 21,'and pullson the bar 20to swing the lever 24 to -open the valve 26, and the valve mechanism doesnot operatetoadmit fluid under )rcsjsure from the dpipe 30 to the pi e 33, an( the springidiol sthe yalve intie steam pipe 8 -open and steam is driven into the room or compartment. It will be evident that this particular means of humidfying the atmosphere is not the only one that can be emiloyed, and applicant does not wish to be un erstood as limiting himself to this-means for inoistening the air. As the percentage of humidity increases, the evaporation from the wet rod 12 becomes less rapid and the rod 12 therefore becomes warmer and expands, and in lengthening it operates, through the lever 18, the fulcrum 21 and the bar Q0 to relieve the lever 24, and the spring is allowed to act on the lever 24 to close the valve 2S. The valve mechanism is then operated to permit fluid under pressure to pass from the pipe 80 into the pipe 33, the diaphra m valve 34 acts on the steam valve 36 and t ie supply of moisture is cut oti. I maintain the water in the trough 14 by a suitable inlet pipe 41 and an outlet pipe 42, which pi es act to keep the water at the same leve but do not permit it to overflow. The amount of water admitted, of course, through the supply pipe is very small,since it is only necessary to suppl what little is consumed in evaporation, an except for the first filling.

Having thus described my invention, what I claim is 1. Means for adjusting a valve of a humidifyin ap aratus consisting of a pair of rods ma e o material havin the same cocfiicient of expansion, means or keeping one of the rods wet, a lever in pivotal relation with the rods and a bar nf material having the same coefiicient of expansion as the pair of rods connectingthe lever and the valve, thebar being proportioned in length so as to maintain its operativeness within a predetermined range of dry bulb temperature the pair of ro s and the bar being separated suitabladistances to give the proper ratios of leverage to the lever. l

2. M eans'for adjusting a valve of a humidif ing apparatus consisting of a pair of rpds aving the same coefficient of expansion, means for keeping one of the rods wet,

a lever in pivotal relation with the rods, a bar having the same coefiicient of expansion as the rods cnnectin the lever with the valve, and means on tie end of one of the rods for ad'usting the lever toward and from the en of the rod, the bar having its length and disposition so regulated that it maintains its operativeness within a predetermined range of dry bulb temperature thepair of rods and the bar being separated suitable distances to give the proper ratios of leverage to the lever.

8. Means for adjusting a valve of a humidif ing apparatus consisting of a pair of rods aving the same coefficient of expansion, means for keeping one of the rods wet, a lever in pivotal relation with one of the rods, a bar in pivotal relation with the 1ever and connected with the valve, and a regulatin screw in the lever and bearin on the ot er rod, the bar being disposed an( pro ortioned so that it is o erative for a pre etermined range of dry ulb temperature, the pair of rods and the bar being separated suitable distances to give the proper ratios of leverage to the lever.

4. Means for adjusting a valve of a humidifying apparatus consisting of three rods, one end of the rods being connected by a lever, and means for keeping one of the rods wet, the wet rod and one of the dry rods having a fixed support, the third rod having one end connected to the valve to o erate it the rods havin such lengths, co e cient of expansion, and eing separated to give the proper ratios of leverage to the ever so as to operate the valve to keep the humidifying means at the point of o crating with a given percentage of humidity regardless of temperature.

In testimony, that I claim the fore oing, I have hereunto set my hand this lOt day of February 1910.

VERNER F. DAVIS.

Witnesses:

WM. H. CAMFIELD, E. A. Pau..

Coplas et this patent may be ebtalned toi' he unta nach, by addressing the Oommlutoner e! Patents Washington, D. 0. 

